Recyclable film for thermoforming

Abstract

Recyclable films having a first layer comprising polyethylene, a second layer comprising high density polyethylene and a hydrocarbon resin, and a third layer comprising polyethylene can be used for thermoformed packaging components. Both the first and third layers have a total density between about 0.92 g / cm 3 and 0.97 g / cm 3 The film structure is advantageous because it can be more easily thermoformed than traditional high density polyethylene films and can maintain the shape formed during the thermoforming process, exhibiting minimal warpage or shrinkage.

Description

[0001] This application is a divisional application of Chinese patent application No. 202080026508.2, filed on April 3, 2020, entitled "Recyclable Film for Thermoforming". Technical Field

[0002] This disclosure relates to membrane structures, particularly high-performance recyclable membranes suitable for thermoforming into packaging components. Background Technology

[0003] High-performance packaging films are used to package many products, such as food, pharmaceuticals, consumer goods, or industrial items. Environmentally sensitive products use specially designed packaging to help protect the product and extend its shelf life until the point at which the consumer can use it. Typically, these packages are made from various types of polymers and additives that provide the properties required to achieve "high performance." The choice of materials for packaging can enhance, in particular, barrier properties, physical properties, or aesthetics. Often, packaging design incorporates multiple materials to achieve several characteristics.

[0004] Combining multiple materials into a single packaging material can create difficulties in determining how to dispose of the packaging after use. Recycling is often most efficient or even possible only when the materials in the packaging are of the same polymer type. Attempts to use recyclable packaging materials, especially those using a single polymer type, result in lower performance and / or significantly higher costs. For example, lower performance characteristics encountered might include visual defects, poorer barrier properties and shorter shelf life, and slower packaging equipment speeds.

[0005] One type of polymer particularly well-suited for recycling is high-density polyethylene (HDPE). This material has been used in milk jugs and other bottles for many years. These bottles are 100% HDPE and provide suitable barrier properties, especially in the case of thick walls. In many countries, there are currently processes in place for the proper collection, sorting, and recycling of these packages.

[0006] However, using high-density polyethylene (HDPE) as the main component has not translated into the most flexible packaging form. Aside from injection molding or blow molding, HDPE has drawbacks that make its use inefficient. For example, in thermoformed flexible packaging, such as trays or cups, HDPE has been found to mold less easily or consistently than other materials such as polystyrene or PVC. HDPE molding can be slower and result in defective molded parts. Furthermore, secondary crystallization of HDPE can cause molded parts to warp and curl within hours and days after molding. For this reason, thermoformed packaging often uses other materials, such as multilayer films with a combination of materials, to obtain good parts at an acceptable rate. These films are not recyclable due to the diversity of materials involved. Summary of the Invention

[0007] The structure and material composition of the thermoformed base component are configured to provide moisture barrier properties, excellent molding and heat-sealing characteristics, and recyclability options. The thermoformable base film forming the base has a high level of polyethylene, making it easy to recycle. Surprisingly, the thermoformable film described herein has an acceptable operating window in the thermoforming process. Also advantageously, the final thermoformed base component retains its original thermoformed shape, resisting warpage and shrinkage.

[0008] In various embodiments disclosed herein, a thermoformable base film is described. This thermoformable base film comprises: a first layer of polyethylene, a second layer of high-density polyethylene and a hydrocarbon resin, and a third layer of polyethylene. The second layer is located between the first layer and the third layer. The first layer and the third layer each have a content of approximately 0.92 g / cm³. 3 and 0.97g / cm 3 The total density between the layers, and each forming the surface of the thermoformable base film. The first layer may additionally contain metallocene linear low-density polyethylene. The second layer may additionally contain a nucleating agent.

[0009] Additionally, the membrane may have a fourth layer located between the first and third layers, the fourth layer comprising high-density polyethylene and inorganic particles. The inorganic particles may be calcium carbonate. The inorganic particles may be present at a level of 5% (by weight, relative to the entire fourth layer).

[0010] The melt flow rate of this thermoformable base film can be at least 20% greater than that of the same thermoformable base film, except that the film does not contain hydrocarbon resin.

[0011] The membrane may also have various other layers, including but not limited to an oxygen barrier layer or central layer comprising an ethylene vinyl alcohol copolymer. If the membrane has a central layer, the central layer comprises an ethylene vinyl acetate copolymer, and the membrane is palindromic. The membrane can be formulated with an overall composition suitable for recycling. For ease of recycling, the membrane can be formulated such that it is substantially free of polyester, ethylene vinyl alcohol copolymer, and polyamide. The thermoformable base membrane has a thermoforming temperature operating window of at least 6°C.

[0012] When heat-sealed to ethylene vinyl acetate material under conditions of 0.5 seconds and 30 PSI, the first layer of the thermoformable base film can have a heat-sealing strength greater than 2,000 g / 25.4 mm.

[0013] Specific embodiments of this thermoformable base include those made of high-density polyethylene with a density of less than 0.93 g / cm³. 3 The first layer is a blend of polyethylene. A specific embodiment of the thermoformable base includes a first layer of medium-density polyethylene.

[0014] The hydrocarbon resin in the second layer may have a loading level of 5% to 10% relative to the thermoformable base film, and the melt index of the thermoformable base film may be between 1.7 and 2.3 g / 10 min (190°C, 2160 g).

[0015] Another embodiment of this thermoformable base film includes one with a content of approximately 0.92 g / cm³. 3 and 0.97g / cm 3 The first layer has a total density between 60 wt% and 90 wt% high-density polyethylene and between 2.5 wt% and 30 wt% hydrocarbon resin, and the second layer has a total density between 0.92 g / cm³. 3 and 0.97g / cm 3 The third layer is the layer with the highest density between the first and third layers. The second layer is located between the first and third layers and has a thickness of 25% to 90% of the total thickness of the thermoformed base film. This embodiment may be substantially free of polyester, ethylene vinyl alcohol copolymer and polyamide.

[0016] In any embodiment, the total density of the thermoformable base film is less than 1.0 g / cm³. 3 .

[0017] In the various embodiments disclosed herein, a thermoforming base is described. The thermoforming base is formed from the thermoformable base film and includes at least one cavity and a flange (i.e., an unformed area) surrounding each of these cavities. Advantageously for the film described herein, the thermoforming base retains the shape formed during the thermoforming process.

[0018] In the various embodiments disclosed herein, the thermoformed base described herein is combined with a product and a cap packaging component to create a packaged product. The cap is hermetically sealed to the flange of the base, and the product is thereby enclosed within these cavities. The cap may contain metal or paper. The cap may be peelably sealed to the base, allowing it to be manually removed. The seal strength between the thermoformed base and the cap packaging component may be at least 2,000 g / 25.4 mm.

[0019] In some embodiments, the cap is a "push-in" cap. In other words, the cavity of the thermoformed base can be manually pressed down, and the product can be pushed through the cap for dispensing. In a preferred embodiment of the packaged product, the cap has: a first outer layer having high-density polyethylene and inorganic particles, a second outer layer having a polyethylene-based material, and a first inner layer having high-density polyethylene and optionally a hydrocarbon resin. In some embodiments of the packaged product, both the base and the cap components are recyclable in the same recycling process.

[0020] It has been discovered that thermoformable base films having at least a first, second, and third layer, as described herein, can be used to produce thermoformable base film parts with excellent results. This is surprising because such thermoformable base films contain a significant amount of polyethylene, which has previously been shown not to possess an acceptable combination of properties for high-performance thermoformable packaging applications. The thermoformable base films described herein offer a key and previously unrealized combination of 1) ease of thermoforming, 2) high moisture barrier properties, and 3) recyclability. Attached Figure Description

[0021] This disclosure will be more fully understood by considering the following detailed description of various embodiments of the disclosure, taken in conjunction with the accompanying drawings, in which:

[0022] Figure 1 This is a schematic cross-sectional view of an embodiment of a thermoformable base film including a first layer, a second layer, and a third layer;

[0023] Figure 2 This is a schematic cross-sectional view of an embodiment of a thermoformable base film including a first layer, a separated second layer, a third layer, and a central layer;

[0024] Figure 3 This is a schematic cross-sectional view of an embodiment of a thermoformable base film including a first layer, a second layer, a third layer, a central layer, and an oxygen barrier layer;

[0025] Figure 4 This is a schematic cross-sectional view of an embodiment of a thermoformable base film including a first layer, a second layer, a third layer, and a fourth layer;

[0026] Figure 5 It is a perspective view of a thermoformed base component including 10 cavities;

[0027] Figure 6 This is a top view showing a thermoformed base component with 12 cavities and flanges;

[0028] Figure 7 It is a schematic diagram of a cross-section of the packaging, including the thermoformed base component, the product, and the cover component;

[0029] Figure 8 A schematic cross-sectional view of an embodiment of a cap component for packaged products; and

[0030] Figure 9 This is a graph showing data from the daily per-cavity weight gain study based on USP 671 (40°C, 75% RH).

[0031] The accompanying drawings illustrate some, but not all, embodiments. The elements depicted in the drawings are illustrative and are not necessarily drawn to scale, and throughout the drawings, the same (or similar) reference numerals denote the same (or similar) features. Detailed Implementation

[0032] This article describes a polyethylene-based, thermoformable base film suitable for packaging products that may be sensitive to oxygen and / or moisture. The capping film can be heat-sealed to a thermoformed base packaging component made from this thermoformable base film, thereby establishing packaging acceptable in high-density polyethylene recycling processes or polyethylene recycling processes. High-performance packaging is suitable for products such as, but not limited to, pharmaceuticals, nutritional foods, medical products, fresh foods, refrigerated foods, shelf-stable foods, consumer goods, cosmetics, and chemicals.

[0033] The structure and material composition of the thermoformable base components are uniquely configured to provide options for moisture barrier properties, good transparency, and recyclability. Surprisingly, the thermoformable films described herein offer an acceptable operating window in the thermoforming process, making the final thermoformable base components easy to thermoform. Equally surprising is that, during thermoforming, the thermoformable base materials described herein are able to maintain their original thermoformed shape, resisting warping and shrinkage.

[0034] The packaging described herein incorporates at least two packaging components. First, there is a thermoforming base component having at least one thermoforming cavity made of a polyethylene-based film. The thermoforming cavity can be deep or shallow and is typically shaped to hold the intended product within it. The thermoforming base film should have a certain thickness to provide the desired stiffness (i.e., rigidity), durability, and barrier properties during thermoforming. Second, there is a lid packaging component. This lid is configured with a film capable of being hermetically heat-sealed to the thermoforming base component, thereby creating protective packaging for the product.

[0035] In some embodiments of this packaging, a high-performance cap component comprising a large amount of high-density polyethylene can be used in conjunction with a thermoformed base. The combination of the thermoformed base component and the cap packaging component provides excellent packaging characteristics while maintaining a highly uniform polymer composition (primarily consisting of polyethylene) to provide the opportunity for recycling the entire package in a single stream (e.g., a high-density polyethylene bottle stream).

[0036] The packaging components described in this article are unique because they are produced using high-density polyethylene while retaining the high-performance characteristics required for demanding packaging applications. The airtight packaging provides superior product protection (i.e., moisture barrier), a good appearance, good molding precision and consistency, good heat resistance, and good seal strength. Packaging with these performance levels has not previously been delivered using materials that can be easily recycled in high-density recycling streams.

[0037] Base packaging components

[0038] like Figure 1As shown, the thermoformable base packaging component is formed from a thermoformable base film 10 having at least a first layer 20, a second layer 30, and a third layer 40, wherein the second layer is located between the first and third layers. The first and third layers may have similar or identical compositions and together constitute about 10% to about 35% of the total thickness (or volume) of the thermoformable base film. The second layer constitutes about 25% to about 90% of the thermoformable base film. In some embodiments of the thermoformable base film, the second layer constitutes about 50% to about 90% of the thermoformable base film. Additional layers may also be present in the thermoformable base film.

[0039] As used herein, the term "layer" refers to a structural unit of a membrane, which is a structure of a single material type or a homogeneous blend of materials. A membrane comprises one or more layers connected to each other. Layers may contain a single polymer, a blend of materials within a single polymer type (i.e., polyethylene), or a blend of various polymer types. Layers may contain metallic materials or other non-polymeric materials and may have additives. The layers of a membrane may be continuous or discontinuous or patterned relative to the membrane. A membrane has two surfaces opposite each other. A layer on one surface of the membrane is not connected to another layer of the membrane at that surface.

[0040] The first and third layers of the thermoformable base film both contain polyethylene, and the total density is approximately 0.92 g / cm³. 3 and 0.97g / cm 3 Between. The first and third layers may contain high-density polyethylene, medium-density polyethylene, or a blend of these with low-density polyethylene. As used throughout this application, the terms "high-density polyethylene" or "HDPE" refer to (a) a polyethylene with a density of about 0.960 g / cm³. 3 Approximately 0.970 g / cm³ 3 (a) The ethylene homopolymer and (b) have a density of approximately 0.940 g / cm³. 3 Approximately 0.958 g / cm³ 3 High-density polyethylene (HDPE) is a copolymer of ethylene and α-olefins (typically 1-butene or 1-hexene). HDPE includes polymers produced using Ziegler or Phillips-type catalysts and polymers produced using single-point metallocene catalysts. HDPE can be bimodal and can be pre-nucleated using nucleating agents. Nucleating agents can be added to HDPE via masterbatch. As used throughout this application, the term "medium-density polyethylene" refers to a density of about 0.926 to 0.940 g / cm³. 3 ethylene homopolymers and copolymers.

[0041] As used throughout this application, the term "nucleating agent" refers to an additive that forms nuclei in a polymer melt to control crystal growth. Nucleating agents can be of any type capable of nucleating high-density polyethylene (HDPE) and can be added at the polymerization point of HDPE or at a later point by adding and melt-blending a masterbatch containing the nucleating agent. Examples of nucleating additives include minerals such as chalk, talc, clay, kaolin, silicates, etc., and organic agents such as salts of aliphatic or aromatic carboxylic acids, metal salts of aromatic phosphorus compounds, quinacridones, and aromatic amides. Other examples of nucleating agents include zinc glycerol, calcium glycerol, calcium hexahydrophthalate, zinc hexahydrophthalate salts, and mixtures thereof. Nucleating agents can be present in the first and third layers of the thermoformable base film at a level of 0% by weight to about 3.5% by weight.

[0042] Examples of prenucleated high-density polyethylene (HDPE) materials potentially suitable for thermoformable base films include grade M6020SB, available from Equistar, and HPS167AB, available from Nova Chemicals. Examples of unnucleated HDPE materials potentially suitable for thermoformable base films include grade M6020, available from Equistar. Examples of nucleating agent masterbatches suitable for thermoformable base films include those available from Milliken. HPN nucleating agent.

[0043] The first and third layers may also contain substances with a density of less than 0.93 g / cm³. 3 The first layer may contain polyethylene with a density of approximately 0.92 g / cm³. 3 Linear low-density polyethylene, metallocene-catalyzed linear low-density polyethylene, ethylene-based plastomers, or low-density polyethylene. Density less than 0.93 g / cm³. 3 Polyethylene can be blended with high-density or medium-density polyethylene, and can be present in the layers in amounts greater than 0.5% by weight, greater than 5% by weight, greater than 10% by weight, or about 30% by weight or more. A density of less than 0.93 g / cm³ can be used in the first layer. 3 Two or more different polyethylene materials. The first and third layers may have the same or different compositions.

[0044] As used in this article, "density less than 0.93 g / cm³" 3 "High-density polyethylene" is a homopolymer or copolymer of ethylene with a density lower than that of medium-density polyethylene, and therefore has significantly different physical properties. The ideal density of polyethylene is 0.88 g / cm³. 3 and 0.93g / cm 3 Between. Density less than 0.93 g / cm³. 3The polyethylene can be an ethylene-based plasmon or a metallocene-catalyzed linear low-density polyethylene. It can be used as a thermoformable base film with a density of less than 0.93 g / cm³. 3 Examples of polyethylene include ATTANE TM 4701 ultra-low density polyethylene (density 0.913 g / cm³) 3 Melt index 1.0 g / 10 min, Vicat softening temperature 94.0 °C, available from Dow Chemical Company; Exceed TM 1018 metallocene-catalyzed ethylene-hexene copolymer (density 0.918 g / cm³) 3 Melt index 1.0 g / 10 min, melting temperature 119 °C, available from ExxonMobil; AFFINITY TM PL1850 is an ethylene-based plastide (density 0.902 g / cm³). 3 Melt index 3.0 g / 10 min, sealing onset temperature 94.0 °C (available from Dow Chemical Company); Exact TM 3139 Ethylene-based plastide (density 0.900 g / cm³) 3 Melt index 7.5 g / 10 min, Vicat softening temperature 80.0℃, melting temperature 95.0℃ (available from ExxonMobil); and DOW TM LDPE 608A low-density polyethylene (density 0.023 g / cm³) 3 Melt index 2.6 g / 10 min, Vicat softening temperature 97.2 °C, melting temperature 113 °C (available from Dow Chemical Company). Density in the first layer is less than 0.93 g / cm³. 3 The polyethylene should have a softening point that allows for heat sealing at a lower temperature (i.e., the cover is heat-sealed) when attached to another package component.

[0045] Regarding the type of polyethylene, the type and presence of the nucleating agent, the total density of the layers, and the blending ratio of the materials, the first and third layers can have the same, similar, or different compositions. The first and third layers can have the same, similar, or different thicknesses.

[0046] The second layer of the thermoformable base film contains high-density polyethylene and a hydrocarbon resin. In some embodiments, the second layer of the thermoformable base film contains a nucleating agent. The second layer can be divided into multiple "second layers" that are separated from other layers. One or more second layers must be between the first and third layers.

[0047] High-density polyethylene (HDPE) should be present in the second layer at an amount of about 60% to about 90% by weight. HDPE may be present in the second layer at an amount greater than 80% or greater than 85%. Two or more different HDPE materials may be present in the second layer. A nucleating agent may be present in the second layer of the thermoformable base film at a level of about 0.2% to about 3.5% by weight.

[0048] As used herein, the phrase "hydrocarbon resin" refers to a low molecular weight product (molecular weight less than about 10,000 Daltons) produced by polymerization of coal tar, petroleum, and turpentine feedstocks. Hydrocarbon resins may include any hydrocarbon resin disclosed in U.S. Patent No. 6,432,496, published August 13, 2002, or U.S. Patent Application 2008 / 0286547, published November 20, 2008, both of which are incorporated herein by reference in their entirety. More specifically, as a non-limiting example, hydrocarbon resins may include petroleum resins, terpene resins, styrene resins, cyclopentadiene resins, saturated alicyclic resins, or mixtures of such resins. Additionally, as a non-limiting example, hydrocarbon resins may include those derived from the polymerization of olefin feedstocks rich in dicyclopentadiene (DCPD), those derived from olefin feedstocks generated during petroleum cracking (e.g., crude C9 feed streams), those derived from pure monomers (such as styrene, α-methylstyrene, 4-methylstyrene, vinyltoluene, or any combination of these or similar pure monomer feedstocks), those derived from terpene olefins (such as α-pinene, β-pinene, or d-limonene), or combinations thereof. Hydrocarbon resins may be fully or partially hydrogenated. Specific examples of hydrocarbon resins include, but are not limited to, those available from Eastman Chemical Company (Kingsport, Tennessee). R1140 hydrocarbon resin, available from Eastman Chemical Company (Kingsport, Tennessee). T1140, available from Arakawa Chemical Industries, Limited (Osaka, Japan). P-140 and available from Hercules Incorporated (Wilmington, Delaware) S135 polyterpene resin.

[0049] Hydrocarbon resins can be present in the second layer in amounts between 0% and 50% by weight. The upper limit of the amount of hydrocarbon resin used can be determined by processing problems (i.e., insufficient melt strength during extrusion) or film properties. For example, high levels of hydrocarbon resin may lead to interlayer adhesion problems or film brittleness. The amount of hydrocarbon used in the second layer will also depend on the type of hydrocarbon resin used and the thickness of the second layer. For example, a thinner second layer may be able to be processed with higher levels of hydrocarbon resin before problems arise.

[0050] In some embodiments of the thermoformable base film, the hydrocarbon resin may be present at a level of up to 30% by weight relative to the second layer. The hydrocarbon resin may be loaded into the second layer at levels between 2.5% and 30%. Some embodiments of the thermoformable film will have a hydrocarbon resin level in the second layer between 5% and 20%. In exemplary embodiments, the hydrocarbon resin is present in an amount of about 15% by weight or about 7.5% by weight. The level of the hydrocarbon resin can be adjusted to control the moisture barrier properties and thermoforming temperature window of the film. Increasing the hydrocarbon resin level increases the moisture barrier properties of the film. Increasing the hydrocarbon resin level increases (i.e., widens) the thermoforming temperature window of the thermoformable base film.

[0051] Any additional material present in the first, second, or third layer of the thermoformable base film, or in other layers of the thermoformable base film, should be acceptable for polyethylene recycling processes. For separation purposes, the thermoformable base film may have a content of less than 1.0 g / cm³. 3 The total density. Any additional non-polyethylene materials can be present at low levels so that they do not disrupt or otherwise hinder the recycling process. Additional materials can be of a type acceptable to the recycling process, such as other types of polyolefin-based materials. Additional materials can be present in conjunction with a compatibilizer system.

[0052] Other layers may be present in a thermoformable base film, as long as these layers do not impair the properties of the film (i.e., the material must be acceptable for polyethylene recycling processes). These other layers may be present anywhere within the thermoformable base film.

[0053] For example, a thermoformable base film may have a central layer. As used herein, a "central" layer is a layer having an equal number of layers on either side of the central layer of a given film. Figure 2 An embodiment of a thermoformable base film 10 is shown, having a first layer 20 forming the surface of the thermoformable base film, a third layer 40 forming the opposite surface of the thermoformable base film, and two second layers 30 separated and spaced apart by a central layer 60. In this example, the central layer has two layers on either side, thus it is located at the center of the thermoformable base film. The central layer may have any composition as described herein, such as having an oxygen barrier material or a bonding material.

[0054] The center layer 60 is particularly useful when producing thermoformable base films using the "collapsed bubble" process. In this process, a multilayer film is produced via a ring co-extrusion process, after which the tube collapses onto itself, combining the two sides into a final film. This process produces a palindromic layer structure, and the center layer contains a material that bonds to itself under warm conditions, such as an ethylene-vinyl acetate copolymer. Thermoformable base films produced by this process must have a first layer and a third layer of the same thickness and composition. Thermoformable base films produced by this process must have a center layer. Thermoformable base films produced by this process must have at least two second layers.

[0055] In some thermoformable base films, such as Figure 3 The illustrated embodiment may include one or more oxygen barrier layers. The oxygen barrier layer should be located between the first and third layers. The oxygen barrier layer contains a material known to restrict oxygen transport across the membrane. One option for the oxygen barrier material is EVOH. In some cases, EVOH may be present along with a compatibilizer that allows EVOH to be incorporated into the polyethylene recycled stream.

[0056] As used herein, "EVOH" refers to an ethylene-vinyl alcohol copolymer. EVOH is also known as a saponified or hydrolyzed ethylene-vinyl acetate copolymer and refers to an ethylene alcohol copolymer having ethylene comonomers. EVOH is prepared by hydrolysis (or saponification) of the ethylene-vinyl acetate copolymer. EVOH is commercially available in resin forms with various percentages of ethylene. Preferably, the ethylene / vinyl alcohol copolymer contains from about 27 mol% to 48 mol% of ethylene, or even 27 mol% to 38 mol% of ethylene.

[0057] Figure 3 An embodiment of a thermoformable base film 10 is shown, comprising a combination of the following options: a first layer 20, a third layer 40, four second layers 30, a central layer 60, two oxygen barrier layers 70, and four adhesive layers 80. This embodiment can be produced using a collapsed foam process, in which case the film is palindromic. Alternatively, the film can be produced using different processes, and the film does not necessarily have to be palindromic. Adhesive layers 80 are used in this embodiment, but can be incorporated into any other embodiment of the thermoformable base film. An adhesive layer is a layer used to bond different layers, in this case, the oxygen barrier layers and the second layers. The need for adhesive layers depends on the materials in adjacent layers. For the thermoformable base film embodiments described herein, polyethylene copolymer-based adhesive layers are typically suitable.

[0058] like Figure 4As shown, the thermoformable base film 10 may have a fourth layer 50, which is high-density polyethylene containing inorganic particles such as calcium carbonate or talc. Adding one or more fourth layers can facilitate precise cutting of the material after thermoforming. One or more fourth layers 50 should be located between the first layer 20 and the third layer 40 of the thermoformable base film 10. The inorganic particles should be present in the fourth layer in an amount of at least 5% by weight or between 5% by weight and 30% by weight. When adding inorganic particles, attention should be paid to a significant increase in the total density of the thermoformable base film. The total density of the thermoformable base sheet should be maintained at 1.0 g / cm³. 3 The following is because this is a key feature used in the separation process (i.e., sorting by floating) during the recycling process.

[0059] In some embodiments of the thermoformable base film, the first or third layer forms the surface of the film. This surface can be the surface of a cover component that is heat-sealed to a thermoformed base made of the thermoformable base film. In this arrangement, the cover is heat-sealed to a polyethylene-containing substrate with a density of approximately 0.92 g / cm³. 3 and 0.97g / cm 3 The density of the first layer between.

[0060] Thermoformable base films can be fully co-extruded or produced through other processes such as lamination or coating.

[0061] In general, thermoformable base films can have a thickness of about 4 mil (102 micrometers) to about 80 mil (2,032 micrometers). Some packaging applications will benefit from thermoformable base films with a thickness of about 8 mil (203 micrometers) to about 50 mil (1,270 micrometers). In some embodiments, the thermoformable base film has a thickness of about 8 mil (203 micrometers) to about 25 mil (635 micrometers).

[0062] Thermoformable base film should have an overall composition suitable for recycling. Thermoformable base film should have an overall composition suitable for recycling in processes that typically accept polyethylene-based materials. The overall composition may also be suitable for recycling in processes that accept high-density polyethylene materials.

[0063] The thermoformable base films described herein can be recycled after their initial use. As used herein, the term "suitable for recycling" means that the film can be transformed into a new, useful article through reprocessing in a polyolefin recycling stream (i.e., a polyethylene-based recycling stream). Reprocessing may involve washing, separation, melting, and molding, among many other steps. Typically, when plastic packaging is recycled through reprocessing, the material is mechanically cut into small pieces, melted, mixed, and reformed into a new product. If multiple incompatible materials are present in the packaging, they interact during reprocessing, resulting in gels, brittle materials, poor appearance, and products that are generally unusable or of poor quality. The use of the term "recyclable" indicates that these drawbacks are generally not present. Qualification as recyclable material is not regulated by any particular agency but can be obtained from specific groups such as the Association of Plastic Recyclers (APR) and How2Recycle. TM The recyclable membrane disclosed herein is applicable to high-density polyethylene-based recycling streams. Introducing the recyclable membrane into any of these recycling pathways via reprocessing should not require additional compatibilizers.

[0064] Recyclability can be achieved by maintaining a high total amount of polyethylene in the overall composition of the thermoformable base film. Any additives used should be kept to a minimum. Any non-polyethylene-based polymers present should be minimized, or may be accompanied by compatibilizers to achieve a recyclable composition. The total density of the thermoformable base film should be maintained at 1.0 g / cm³. 3 the following.

[0065] To further advance efforts towards a recyclable overall composition, some embodiments of thermoformable base membranes are free of polyester materials. Polyester materials are typically used in membranes due to their ease of thermoforming, rigidity, and transparency. However, the presence of polyester can significantly hinder membrane recyclability.

[0066] To further achieve a recyclable overall composition, some embodiments of thermoformable base membranes do not contain EVOH material. EVOH is typically used in membranes because it is a thermoformable oxygen barrier material. However, the presence of EVOH can significantly hinder membrane recyclability.

[0067] To further advance efforts towards a recyclable overall composition, some embodiments of thermoformable base membranes are free of polyamide materials. Polyamide materials are typically used due to their ease of thermoforming, durability, and rigidity. However, the presence of polyamide can significantly hinder membrane recyclability.

[0068] Thermoformable base films can be free of polyester, EVOH, and polyamide. Thermoformable base films can also be free of fiber-based materials.

[0069] It has been discovered that thermoformable base films having at least a first, second, and third layer, as described herein, can be used to produce thermoformable base film parts with excellent results. This is surprising because such thermoformable base films contain a significant amount of polyethylene, which has previously been shown not to possess an acceptable combination of properties for high-performance thermoformable packaging applications. The thermoformable base films described herein offer a key and previously unrealized combination of 1) ease of thermoforming, 2) high moisture barrier properties, and 3) recyclability.

[0070] Most surprisingly, the thermoforming characteristics of the thermoformable base film described herein are noteworthy. Thermoforming is a process in which the film is heated above a minimum temperature to soften the polymer to the point where it can be physically molded into a desired shape, and then heated below a maximum temperature where the film is melting and cannot be networked. It is well known that for thermoforming, film or sheet structures containing high-density polyethylene material have a very narrow temperature window (the delta between the minimum and maximum processing temperatures). Thermoformable base films containing a second layer using hydrocarbon resins as described herein can increase the thermoforming temperature window by up to 100% or even 200% compared to films without hydrocarbon resins in the second layer. Due to the more forgiving molding temperature range, even a small amount of hydrocarbon resin (i.e., 2.5%) in the second layer of the thermoformable film can significantly affect the ease of thermoforming the film.

[0071] Equally surprising is that the thermoformable base film described herein, despite having a high level of polyethylene, retains the shape formed during the thermoforming process. In other words, thermoforming substrates produced from the thermoformable base film can be thermoformed without experiencing post-thermoforming warping or curling. Furthermore, any shrinkage that may occur after thermoforming is significantly reduced or eliminated. This result is the opposite of previous thermoformed films containing high-density polyethylene.

[0072] Advantageously, thermoformable base films exhibit excellent moisture barrier properties. Moisture barrier properties depend on the layer composition. One way to increase moisture barrier properties is to increase the amount of hydrocarbon resin or nucleating agent in the second layer. Another way to increase moisture barrier properties is to use bimodal high-density polyethylene. The moisture barrier properties of thermoformable base films are important because they allow this material to replace other standard molded films (such as PVC) used for packaging moisture-sensitive products that may not be easily recycled.

[0073] Packaged products

[0074] Thermoformable base film can be formed into packaging components (thermoformable bases) and used in conjunction with other packaging components (e.g., lids) to produce packaging. Thermoformable bases can be produced from thermoformable base film using a thermoforming process employing heat and pressure (mechanical and / or vacuum). The thermoformable base can be highly rigid and inflexible, or it can be flexible while still maintaining the thermoformed shape. The thermoformable base described herein has at least one cavity for holding the product and flanges surrounding each of these cavities. The flanges are typically unformed areas of the film and serve as locations for connecting the thermoformable base to other packaging components (potentially lids), another thermoformable base component, or other packaging components.

[0075] Figure 5-7 Examples of thermoforming bases are illustrated. In these embodiments, the thermoforming base 100 has a plurality of (10 or 12) cavities 110 surrounded by flanges 120. The dimensions of such cavities can be specifically designed to hold a single pharmaceutical tablet or capsule. Alternatively, the cavities of the thermoforming base can be larger and hold multiple product parts. This application contemplates cavities of all numbers, sizes, and shapes.

[0076] like Figure 7 As shown in the packaged product embodiment, each cavity 110 is surrounded by a flange 120. The flange 120 of the thermoformed base 100 should have a non-bending area for attachment to another packaging component, such as a cap packaging component 200. Each cavity encloses the product 1100. In this embodiment, the cap component is hermetically sealed to a flange in the area surrounding each cavity of the thermoformed base. Alternatively, the cap may be attached to the thermoformed base at a flange in the area encompassing the entire periphery of all cavities (and not between cavities).

[0077] The thermoformed base can be attached to another packaging component via a seal, preferably an airtight seal. In this way, the product inside the packaging is completely enclosed within a cavity and protected by the thermoformed base and other packaging components. The exchange of gases, liquids, microorganisms, or other materials is limited to those that can pass through the packaging components, as the airtight seal does not allow passage through the spaces between the components.

[0078] There are no restrictions on the products contained within the cavity of the thermoformed base. The packaging may contain environmentally sensitive products, such as pharmaceuticals or food. Products may require physical protection, such as delicate medical devices. To protect consumers, products that may be contained, such as medicines or cleaning agents, should be in child-proof packaging. Products may be suitable for easy dispensing, such as chewing gum or candy.

[0079] If the packaged product includes a cap packaging component, the cap can have any composition suitable for the application. The cap should have a heat-sealable outer layer configured to allow it to be easily attached to the thermoformed base by heat sealing. The seal between the cap packaging component and the thermoformed base can be peelable (i.e., easily separable manually with a peel strength of less than about 2,500 g / 25.4 mm) or fused.

[0080] If the cap is fused and sealed to the thermoformed base, the cap can be configured and / or designed such that the product can be pushed through the cap for dispensing. In particular, for applications containing packaged products such as pharmaceutical tablets, gel blocks, etc., the cavity of the thermoformed base can be flexible enough that a consumer can manually press down the cavity, forcing the product through the cap component for dispensing. The seal strength between the thermoformed base and the cap packaging component can be at least 2,000 g / 25.4 mm.

[0081] The cap packaging component should have moisture and / or oxygen barrier properties similar to those of the thermoformed base. Materials typically used for high-performance caps include, but are not limited to, metal or paper layers. These metal and / or paper layers may be laminated or otherwise bonded to a polymer layer, including a heat-sealing layer. The cap may be printed, scored, or otherwise modified for specific properties.

[0082] Figure 8 An example of a cap component that can be sealed to a thermoformed base to provide a packaged product is shown. The cap 200 may have a first outer layer 210 containing high-density polyethylene and inorganic particles such as talc or calcium carbonate. This type of outer layer provides high heat resistance during the process of sealing the cap component to the thermoformed base component to enclose the product. The cap may have a second outer layer 220 containing a polyethylene-based material, which is formulated to heat-seal to the thermoformed base at relatively low temperatures. The cap may have a first inner layer 230, which is formulated to have excellent moisture barrier properties. An example of a blend of materials that can be well used as a moisture barrier layer is high-density polyethylene and a hydrocarbon resin. This blend is similar to the second layer of a thermoformable base component. Figure 8 One advantage of the illustrated cap is that it has similar recyclability to the thermoformable base film described herein, allowing the entire package to be recycled together without separation. In some embodiments, the entire package, including the thermoformed base and the cap component, can be recycled together in a high-density polyethylene recycling process or another polyethylene recycling process.

[0083] Instances and data

[0084] Improvement of thermoforming temperature window

[0085] Compared to previously known polyethylene-based films, the structure discussed herein offers a significant advantage in terms of ease of thermoforming. Substrate packaging components formed from the substrate packaging film disclosed herein retain their molded shape without warping due to polymer crystallization. Thermoformed parts maintain the same dimensions and shape for minutes, hours, days, and weeks after thermoforming. Furthermore, the material is easier to thermoform due to a wider molding operation window (i.e., temperature).

[0086] Typically, it is best to perform thermoforming processes when the film is heated to a temperature between the polymer's softening and melting temperatures. In the case of high-density polyethylene (HDPE), this temperature window for thermoforming is usually quite small—a few degrees. This makes the process of thermoforming standard HDPE films very difficult to control. It has been found that the base packaging film described herein has a much wider thermoforming temperature operating window, capable of softening at lower temperatures without exhibiting sag. As used herein, the "thermoforming temperature operating window" can be defined by the difference between the minimum and maximum heating temperatures in the molding process described below.

[0087] Furthermore, films based on high-density polyethylene are known to exhibit secondary crystallization, causing significant shrinkage and warping of parts over time spans of minutes, hours, or days after thermoforming. The thermoformable substrate packaging film described herein does not suffer from this secondary crystallization, thus allowing the use of these materials in the thermoforming of critical components such as packaging blister packs.

[0088] The thermoformable substrate films, Examples 1, 2, and Comparative Example 1, were manufactured using a standard blown film co-extrusion process, with the foam collapsing into individual palindromic films. Details of these films are shown in Table 1, and their structures are shown in... Figure 2 Example 1 comprises a first layer containing high-density polyethylene and a nucleating agent, a second layer containing high-density polyethylene, a hydrocarbon resin, and a nucleating agent, and a third layer containing high-density polyethylene and a nucleating agent. Due to the collapsed foam process used to manufacture the membrane, the second layer is divided into two layers separated by a central layer containing an ethylene vinyl acetate copolymer. Similarly, the first and third layers must have the same composition. Example 2 and Comparative Example 1 are processed similarly. The second layer of Comparative Example 1 does not contain a hydrocarbon resin, the second layer of Example 1 contains about 7.5% by weight of a hydrocarbon resin (18.75% loaded with 40% masterbatch), and the second layer of Example 2 contains about 15% by weight of a hydrocarbon resin (37.5% loaded with 40% masterbatch).

[0089] Examples 1, 2, and Comparative Example 1 are shown in the section on a Uhlmann B 1240 blister packer used as a forming network for thermoformable substrate films. Uhlmann uses ten cavities (e.g., in thermoformable substrate films) in these films. Figure 5(As shown). The tools used created cavities designed to fit the dimensions of capsules with a size of zero (0). The material was circulated through the thermoforming process at a rate of 35 cycles / minute. Prior to forming, Uhlmann used top and bottom contact heating in three indices.

[0090] To evaluate the temperature window for forming a suitable cavity, the contact heating temperature was slowly increased, and the formed capsule was evaluated at each temperature. It was found that for Comparative Example 1, the minimum heating temperature required to achieve a fully formed capsule was 112°C. The cavity was considered fully formed when there was evidence of a vacuum opening on the cavity surface. For Comparative Example 1, 115°C was determined as the maximum heating temperature when the material began to melt, deform, and exhibit poor aesthetics. Therefore, this material has a temperature window of approximately 3°C for a thermoformable cavity.

[0091] The thermoformable base of Example 1 was tested using the same method as Comparative Example 1. The lowest temperature was found to be 109°C, and the highest temperature was 115°C. This represents a 6°C operating temperature window, a 100% improvement compared to the thermoformable base of Comparative Example 1. The thermoformable base of Example 2 was tested using the same method as Comparative Example 1. The lowest temperature was found to be 106°C, and the highest temperature was 115°C. This represents a 9°C operating temperature window, a 200% improvement compared to the thermoformable base of Comparative Example 1.

[0092] Table 1: Details of Thermoformable Base Film

[0093]

[0094]

[0095] HDPE1 = High-density polyethylene, melt index = 2.0 g / 10 min (190°C, 2160 g), density = 0.96 g / cc

[0096] HDPE3 = High-density polyethylene, melt index = 1.2 g / 10 min (190°C, 2160 g), density = 0.967 g / cc

[0097] HC MB = Hydrocarbon masterbatch containing 40% hydrocarbons and 60% high-density polyethylene

[0098] Nuc MB = nucleating agent masterbatch containing 4% nucleating agent and low-density polyethylene

[0099] EVA1 = ethylene vinyl acetate copolymer, vinyl acetate content = 12%, density 0.93 g / cc

[0100] EVA2 = ethylene vinyl acetate copolymer, vinyl acetate content = 26%, density 0.95g / cc

[0101] 2 MVTR test conditions: ASTM 1249, 100°F and 90% Rh conditions

[0102] The melt flow index of thermoformable base films was measured using ASTM D1238-10 and conditions of 190°C and 2,160 g. Each film was tested five times, and the average of the five tests was reported. The melt flow rate of Comparative Example 1 was approximately 1.55 g / 10 min. The melt flow rate of Example 1 was found to be approximately 1.9 g / 10 min. This is at least 20% greater than that of the same thermoformable base film (Comparative Example 1) except that the film does not contain hydrocarbon resins. A third thermoformable base film, similar in thickness to Example 1 with a total hydrocarbon resin load of 10% by weight, was found to have a melt flow rate of approximately 2.28 g / 10 min. Ideally, the thermoformable base film should have a hydrocarbon resin load that increases the melt flow rate of the thermoformable base film by at least 20% or between 20% and 50%.

[0103] High oxygen barrier version

[0104] Example 3 of the thermoformable base film was manufactured using a standard blown film co-extrusion process, where the foam collapsed into individual palindromic films. Details of these films are shown in Table 2, and their structures are shown in... Figure 3 Example 3 includes a first layer containing high-density polyethylene and a nucleating agent, a second layer containing high-density polyethylene, a hydrocarbon resin, and a nucleating agent, a third layer containing high-density polyethylene and a nucleating agent, and an oxygen barrier layer containing EVOH and an adhesive layer. The second layer is divided into four distinct layers separated by the other layers. The oxygen barrier layer is divided into two distinct layers separated by the other layers. The first and third layers have the same composition.

[0105] Table 2: Details of Thermoformable Base Film

[0106]

[0107]

[0108] HDPE1 = High-density polyethylene, melt index = 2.0 g / 10 min (190°C, 2160 g), density = 0.96 g / cc

[0109] HDPE3 = High-density polyethylene, melt index = 1.2 g / 10 min (190°C, 2160 g), density = 0.967 g / cc

[0110] HC MB = Hydrocarbon masterbatch containing 40% hydrocarbons and 60% high-density polyethylene

[0111] Nuc MB = nucleating agent masterbatch containing 4% nucleating agent and low-density polyethylene

[0112] EVA1 = ethylene vinyl acetate copolymer, vinyl acetate content = 12%, density 0.93 g / cc

[0113] EVA2 = ethylene vinyl acetate copolymer, vinyl acetate content = 26%, density 0.95g / cc

[0114] MAgPE = Maleic anhydride-grafted polyethylene

[0115] EVOH = Ethylene-vinyl alcohol copolymer, 38 mol% ethylene

[0116] 1 OTR test conditions: ASTM F1927, 73°F and 0% Rh.

[0117] Weight gain research

[0118] Weight gain studies were conducted according to Method B of ASTM D7709-12, comparing the weight gain per cavity of packages including thermoformed bases according to this disclosure and other blister packaging industry standard materials. The blister packs contained ten cavities formed into blister packs of zero size. Weight gain was calculated using a test unit with five blister packs. The blister packs were filled with desiccant (previously stored in vacuum-packed foil packaging) and sealed on the aforementioned Uhlman B1240 packaging equipment. Storage conditions used were 40°C and 75% RH.

[0119] The weight gain studies included thermoforming substrates from two different thermoformable base films. The first is Example 2, described in Table 1 above. The second is Example 4, further described in Table 3, which is a 10 mil white thermoformable base film.

[0120] Table 3: Details of Thermoformable Base Film

[0121]

[0122] HDPE1 = High-density polyethylene, melt index = 2.0 g / 10 min (190°C, 2160 g), density = 0.96 g / cc

[0123] HDPE3 = High-density polyethylene, melt index = 1.2 g / 10 min (190°C, 2160 g), density = 0.967 g / cc

[0124] HC MB = Hydrocarbon masterbatch containing 40% hydrocarbons and 60% high-density polyethylene

[0125] Nuc MB = nucleating agent masterbatch containing 4% nucleating agent and low-density polyethylene

[0126] CaCO3 MB = Calcium carbonate masterbatch containing polyethylene with an inorganic content greater than 30% White MB = White masterbatch containing polyethylene and titanium dioxide

[0127] EVA1 = ethylene vinyl acetate copolymer, vinyl acetate content = 12%, density 0.93 g / cc

[0128] EVA2 = ethylene vinyl acetate copolymer, vinyl acetate content = 26%, density 0.95g / cc

[0129] Both thermoformed bases, molded into blister packs, are filled with desiccant and sealed with cap A. Cap A has a heat-resistant outer layer containing high-density polyethylene and inorganic particles (calcium carbonate), an inner layer containing high-density polyethylene and a nucleating agent, and a heat-sealed outer layer containing a polyethylene-based plasmon.

[0130] The results of weight gain studies can be found in Figure 9 As seen in the example, the combination of base and cap A in Example 2 resulted in a single-cavity delivery rate of approximately 0.34 mg / cavity·day. The combination of base and cap A in Example 4 resulted in a single-cavity delivery rate of approximately 0.45 mg / cavity·day. In contrast, similar tests using a molded film of 10 mil PVC / 90 gsm PVDC / 1 mil PE with a 1 mil soft-tempered foil cap resulted in a delivery rate of approximately 0.54 mg / cavity·day, and a molded film of 7.5 mil PVC / 2 mil Aclar with a 1 mil soft-tempered foil cap resulted in a delivery rate of approximately 0.16 mg / cavity·day. The thermoformed base described herein provides moisture delivery rates suitable for pharmaceutical packaging while enabling single-flow recyclability.

[0131] Improvements in cutting

[0132] While packaging was being assembled on the Uhlman B1240 packaging equipment, the cutting performance of the thermoformable base film could also be evaluated. After sealing the packaging, the blister card was cut from the network. It was observed that the thermoformable film of Example 4 was cut more precisely without damaging the edges of the blister card compared to other thermoformable base films that did not contain a layer containing inorganic particles (calcium carbonate).

[0133] Heat sealing research

[0134] The heat seal strength was investigated by varying the total density of the first layer. Flat samples of thermoformable base material containing various blends in the first layer were heat-sealed onto a capping material (Cap A described in the weight gain study above), and the seal strength was measured. A heat seal was formed using a flat sealing strip under conditions of 30 PSI pressure and 0.5 seconds dwell time. Temperatures were varied to understand how the first layer blends altered the seal strength at a given sealing temperature. The seal strength was tested by loading a one-inch (25.4 mm) heat-sealed film strip onto a tensile testing unit and pulling the heat seal apart at an angle of 180 degrees and a speed of 12 in / min. Testing was conducted at 73°F and 50% humidity. Each data point in the table below is the average of three tests, with peak forces recorded.

[0135] When the cap remains bonded and the tensile strength of the film begins to weaken below the bond strength, the heat seal peels off under all sealing conditions except 130°C.

[0136] It was found that a stronger seal (higher heat-sealing strength) can be obtained when a low-density material with a high load is present in the first layer. Up to approximately 50% by weight of a material with a density of less than 0.93 g / cm³ can be used in the first layer. 3 It uses polyethylene without other side effects, such as adhesion to the heating plate or thermoforming problems.

[0137] Table 4: Heat Seal Strength Data

[0138]

[0139]

[0140] Further research on the heat seal strength provides data in Table 5. The tests were conducted as described above, except that a flat sealing strip was used to form the heat seal, accompanied by a pressure of 40 PSI and a dwell time of 1.0 second.

[0141] Table 5: Heat Seal Strength Data

[0142]

[0143] Example

[0144] Examples of thermoformable base films:

[0145] A. A thermoformable base film, comprising:

[0146] Contains at least one type of polyethylene and has a content of about 0.92 g / cm³. 3 and 0.97g / cm 3 The first layer with the total density between them

[0147] A second layer comprising high-density polyethylene and hydrocarbon resin, and

[0148] Contains at least one type of polyethylene and has a content of about 0.92 g / cm³. 3 and 0.97g / cm 3 The third layer of total density between

[0149] The second layer is located between the first layer and the third layer, and the thermoformable base film retains the shape formed during the thermoforming process after thermoforming.

[0150] B. The thermoformable base film according to any other embodiment further includes a fourth layer comprising high-density polyethylene and inorganic particles, wherein the inorganic particles are present in the fourth layer at a level of at least 5% by weight, and wherein the fourth layer is between the first layer and the third layer.

[0151] C. The thermoformable base film according to Example B, wherein the inorganic particles are calcium carbonate.

[0152] D. The thermoformable base film according to any other embodiment, wherein the first layer is high-density polyethylene with a density of less than 0.93 g / cm³. 3 Blends of polyethylene.

[0153] E. The thermoformable base film according to any other embodiment, wherein at least one polyethylene in the first layer is medium-density polyethylene.

[0154] F. The thermoformable base film according to any other embodiment further includes an oxygen barrier layer comprising an ethylene vinyl alcohol copolymer, wherein the oxygen barrier layer is located between the first layer and the third layer.

[0155] G. The thermoformable base film according to any other embodiment, wherein the first layer and the third layer each form the surface of the thermoformable base film.

[0156] H. A thermoformable base film according to any other embodiment, wherein the thermoformable base film has a thermoforming temperature operating window of at least 6°C.

[0157] I. The thermoformable base film according to any other embodiment, wherein the hydrocarbon resin is present in an amount of 5% to 10% by weight relative to the thermoformable base film, and wherein the melt index of the thermoformable base film is between 1.7 and 2.3 g / 10 min (190°C, 2160 g).

[0158] J. A thermoformable base film, comprising:

[0159] Contains high-density polyethylene and materials with a density of less than 0.92 g / cm³. 3 The first layer of polyethylene,

[0160] A second layer comprising 60% to 90% by weight of high-density polyethylene and 2.5% to 30% by weight of hydrocarbon resin, and

[0161] Contains at least one type of polyethylene and has a content of about 0.92 g / cm³. 3 and 0.97g / cm 3 The third layer of total density between

[0162] The second layer is located between the first layer and the third layer, and the thickness of the second layer is 25% to 90% of the total thickness of the thermoformable base film.

[0163] K. The thermoformable base film according to any other embodiment, wherein the total density of the thermoformable base film is less than 1.0 g / cm³. 3 .

[0164] L. A thermoformable base film according to any other embodiment, wherein the thermoformable base film is substantially free of polyester, ethylene vinyl alcohol copolymer and polyamide.

[0165] Examples of thermoformed bases:

[0166] M. A thermoformed base comprising

[0167] The thermoformable base film according to any embodiment AL

[0168] At least one cavity, and

[0169] The flange surrounding each of these cavities.

[0170] N. The thermoforming base according to embodiment M, wherein the thermoforming base retains the shape formed during the thermoforming process.

[0171] Examples of packaged products:

[0172] O. A packaged product comprising:

[0173] The thermoformed base according to embodiment M or N

[0174] Cover packaging components, and

[0175] product,

[0176] The cap packaging component is hermetically sealed to the flange of the thermoforming base, and the product is enclosed in at least one cavity of the thermoforming base.

[0177] P. The packaged product according to Example O, wherein the cap packaging component includes a heat-sealing layer and a layer comprising at least one of metal or paper.

[0178] Q. The packaged product according to any other embodiment, wherein the cap packaging component is peelably sealed to the flange of the thermoformed base.

[0179] R. The packaged product according to embodiment O, Q, S or T, wherein both the thermoformed base and the cap packaging component are recyclable in the same recycling process.

[0180] S. The packaged product according to any other embodiment, wherein at least one cavity of the thermoformed base can be manually pressed down, and the product can be pushed through the cover packaging component for product dispensing.

[0181] T. The packaged product according to embodiment O, Q, R or S, wherein the cap packaging component includes

[0182] The first outer layer consists of high-density polyethylene and inorganic particles.

[0183] A first inner layer comprising high-density polyethylene and optionally a hydrocarbon resin, and

[0184] It includes a second outer layer made of polyethylene-based material.

[0185] U. The packaged product according to embodiments O, P, Q, R, S or T, wherein the seal strength between the thermoformed base and the cap packaging component is at least 2,000 g / 25.4 mm.

Claims

1. A thermoformable base film, comprising: Contains high-density polyethylene and materials with a density of less than 0.92 g / cm³. 3 The first layer of polyethylene, A second layer comprising 60% to 90% by weight of high-density polyethylene and 2.5% to 30% by weight of hydrocarbon resin, and Contains at least one type of polyethylene and has a content of 0.92 g / cm³. 3 and 0.97 g / cm 3 The third layer of total density between The second layer is located between the first and third layers, and the thickness of the second layer is 25% to 90% of the total thickness of the thermoformable base film. Hydrocarbon resins refer to low molecular weight products with a molecular weight of less than 10,000 Daltons produced by polymerizing coal tar, petroleum and turpentine raw materials.

2. The thermoformable base film according to claim 1, wherein the total density of the thermoformable base film is less than 1.0 g / cm³. 3 .

3. The thermoformable base film according to claim 1, wherein the thermoformable base film is free of polyester, ethylene vinyl alcohol copolymer and polyamide.

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